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Friday, October 21, 2016

Phragmipedium kovachii

Phragmipedium kovachii, the most notorious orchid discovery within recent memory, is flowering now in the Tropical High Elevation House.

It's growing high on the waterfall, perched on mossy rocks among two other slipper orchids, Phragmipedium besseae and Phragmipedium schlimii. This is the first flowering for our plant, which is a laboratory produced seedling purchased from Piping Rock Orchids in 2009.

In the wild, Phragmipedium kovachii grows in cloud forests at 2,000 meters elevation near Moyobamba, Peru on limestone seepage sites. Since it first caught the attention of growers and scientists outside of Peru, P. kovachii has practically become a poster child for bad behavior within the horticultural/botanical community -the illegal poaching of a protected orchid by a private collector, followed by an astonishing display of poor judgement by the botanists who took possession of it. You can find a detailed account of the story in Craig Pittman's The Scent of Scandal (2012 University of Florida Press). Pittman is a reporter for the Tampa Bay Times who has covered the kovachii story since 2003. It's a fascinating story and it underscores the importance of following the law when self interest, science and the law conflict. I think of the kovachii story as a cautionary tale and I believe Pittman's account should be required reading for anyone who works with orchids at a botanical garden.

Friday, September 9, 2016

Bullish on Stanhopeas

Stanhopea hernandezii
For a long time I thought of Stanhopea hernandezii as a sort of junior sized version of Stanhopea tigrina, that mastodon of the stanhopeas. Both give the impression of a massive cranium and formidable tusks. But it wasn't until this summer when we flowered both species simultaneously that I was able to compare them side by side.
Stanhopea tigrina
In profile, it's easy to see that the the bottom of the hypochile is rounded like a bowl in hernandezii, but flattened in tigrina.
Stanhopea tigrina, a second color form
Stanhopea hernandezii, dorsal view
The horns are round in cross section and slender in hernandezii, but flattened and broad near the base in tigrina.
Stanhopea tigrina, dorsal view
Stanhopea tigrina, dorsal view
Stanhopea hernandezii, lip and column
Notice the striking difference in the columns of the two species: hernandezii's narrow column compared with tigrina's broadly winged column.
Stanhopea tigrina, lip and column
Stanhopea tigrina, lip and column
Stanhopea hernandezii, lip
With the column removed you can see how much broader the epichile is in tigrina than in hernandezii.
Stanhopea tigrina, lip
Stanhopea tigrina, lip
Stanhopea hernandezii, lip in ventral view
Stanhopea tigrina, lip in ventral view
Stanhopea tigrina, lip in ventral view
Stanhopea hernandezii, column
Stanhopea tigrina, column
Stanhopea tigrina, column
Stanhopea hernandezii and tigrina are both endemic to Mexico. S. hernandezii occurs on the southwestern slopes of the Mexican plateau at about 1,600 to 2,000 meters elevation in the states of Morelos, Mexico and Michoacan. I can't find referennce to a specific pollinator for hernandezii. The largest fragrance components measured by Gerlach (in Lankesteriana 2010) are cinnamyl acetate (64%) and benzyl acetate (11%).

Stanhopea tigrina is known from  the eastern slopes of the plateau at about 1200 to 1800 meters in the states of Tamaulipas, Hidalgo, Puebla and Vera Cruz. Its pollinator is Euglossa viridissima. The chocolate fragrance described so often in the literature (but which I cannot discern in our plants) derives from the combination of phenylethyl-acetate, a primary component of the fragrance, and vanilline, one of the secondary components, according to Rudolf Jenny.

Our S. hernandezii, which we received from a commercial nursery as S. ecornuta, flowered in August and probably won't be on display again until next summer. On the other hand, we have quite a few S. tigrina in our collection. The flowers only last about three days, but it's definitely worth stopping by to try to catch them when they flower in August and September. They are magnificent.

Tuesday, August 9, 2016

Our War On Slugs

These days, 7 am finds me iphone flashlight in hand, visiting each greenhouse, searching the orchid collection for slugs, who I then crush under foot. This summer has brought an unusual amount of slug activity in all of our greenhouses, an unexpected development in the middle of a bright dry summer. They have made their way into pots and hanging baskets, eating root tips, new shoots, young flower spikes and flowers.

One triumph in our war on slugs has been among the Bucket Orchids (Coryanthes), usually a prime favorite of slugs, bush snails, cockroaches and practically any other pest you can name. Everybody, it seems, loves a Coryanthes. But this year the Coryanthes are producing flush after flush of absolutely pristine new roots and shoots. Our secret weapon: diatomaceous earth applied to bare root plants.

Diatoms are unicellular algae with lots of silica in their cell walls. Silica is the major constituent of sand, but it is also found in living organisms. The fossilized remains of diatoms are mined from deposits in the western US, Canada and Germany. The granulated product has industrial uses in filtration systems. Diatoms can also be milled to create a talcum-like powder, called diatomaceous earth, which is abrasive, porous and hygroscopic (moisture absorbing). Diatomaceous earth kills insects and mollusks by abrasion and dehydration.

We began our campaign against slugs on our Coryanthes two years ago. The battle plan had two phases: Remove their sanctuary and then apply treatment. First, we removed all of our Coryanthes from their pots and washed away the mossy medium and the slug eggs; then we mounted the plants on wooden rafts or tree fern slabs so that their roots were exposed and there were fewer places for mollusks to hide.

We began applying diatomaceous earth to our Coryanthes at the height of the slug and bush snail season. Bush snails are tiny. Dozens can hide in the crevices between pseudobulbs. A good way to monitor slug and snail populations is to check the exterior of the raft an hour after watering. Before treatment, I found at least one slug and 10 to 50 bush snails on each wooden raft. We applied diatomaceous earth weekly throughout the spring and summer to the exposed roots, in between the pseudobulbs and to the leaves.

This summer, after renewed applications, there are 0 to 2 bush snails per plant and no sign of chewing damage to root tips or leaves from slugs or cockroaches. We plant to continue applications through the autumn.

A few tips for using diatomaceous earth for slug, snail and cockroach control:

  • Look for "Food Grade Diatomaceous Earth" in order to get freshwater diatoms. Avoid "Pool Grade," which is saltwater-derived.
  • Keep the package sealed and out of the greenhouse or any other humid environment. The powder is highly porous and once it absorbs water from the atmosphere, it loses its ability to dehydrate pests.
  • Wear a dust mask. Silica dust is harmful to lung tissue.
  • Apply diatomaceous earth once a week to the entire plant and its mount when the surfaces are dry: the new shoots, leaves, flower spikes, the slab and in between pseudobulbs. Let it sit at least overnight before you water again, since water will wash it away.
  • Any soft brush will work as an applicator, but I like the idea of battling an enemy with a cosmetic brush. Drugstores carry them.

Sunday, July 31, 2016

Catasetum expansum x 3

In the stranger-than-fiction world of Catasetum flowers -where male and female flowers look so different that they were once classified as different species, and male flowers fire their pollen like missiles -it is the male flowers that are the peacocks and warrior princes with bold colors, sometimes elaborately fringed, toothed or spotted. Male Catasetum expansum flowers have an especially large shield shaped lip. In the center of the lip is a cavity, like a truncated spur, with thick fleshy walls. The cavity doesn't secrete nectar like a spur, but is a source of fragrance for fragrance-collecting Euglossine bees.

This week in our back up greenhouses, we have three different color forms of male Catasetum expansum flowers. First in this regiment is a handsome olive color form with a blood red center and plenty of red war paint. Release of the pollen masses is triggered by a touch to the downward pointing bristle in the center. In the photo above, notice that the flower in the upper left corner still has its pollen payload, while the flower in the center has already fired its two pollen masses.

Our second color form has pale green petals and sepals against a rich yellow-gold lip.

The most common form in our collection is a soft mint nonpareil color, to my eye the most soothing of the three. Catasetum expansum has a surprising range of color forms for a species with a relatively small distribution -northeastern Ecuador, where it grows as an epiphyte in seasonally dry forests from sea level to 1500 meters elevation.

Sunday, July 17, 2016

Summer Orchid Fragrances

It is fascinating to observe all the different ways in which visitors and staff like to experience the orchids here. Many people like to experience the flowers through the lens of their camera, lingering on visual details. Others visit each and every flower, inhaling deeply. For connoisseurs of fragrance, summer is without a doubt the best time to visit the Orchid Center. Here are a few of the best this week.

Phalaenopsis bellina is perhaps the most fragrant of the moth orchid species. "Fruit Loop orchid" is the common name suggested by Eric Christenson, the taxonomist who separated bellina from the closely related violacea on the basis of fragrance and morphological differences. Its fragrance is blend of many compounds, including geraniol, which has a rose-like scent attractive to bees; and linalool, a floral/spicy fragrance. The quantity and quality of an orchid fragrance can be dependent on the time of day, and you may notice that our bellina seedlings are almost scentless in the early morning and very fragrant later in the day.

Anguloa uniflora, one of our tulip orchid species, smells like wintergreen, an unexpected but wonderful pairing. Wintergreen is the fragrance associated with methyl salicylate, a volatile compound that is a common component in floral fragrances that attract male Euglossine bees. The composition of the fragrance of an orchid species can vary from plant to plant to a striking degree. If you take a moment to smell several of our unifloras, you will notice that one of our accessions produces an especially powerful wintergreen fragrance, the others less so.

I'm not going to talk about the slug who brazenly made his way to the top of a floral bract while I was composing this shot, except to say that he is no longer with us.

Anguloa virginalis has a sweet, but somewhat medicinal fragrance composed of 1.8-cineole, limonene, myrcene and pinene. By mid afternoon, our three plants can fill the back of the High Elevation House with an invisible fragrance plume.

Peristeria lindenii was here and gone in a flash typical of short-lived Stanhopeinae flowers, but with a complex fragrance unlike any other I that I know of -like a fruit salad over a layer of eucalyptus (cineole).

The practice of dipping your nose in every beautiful orchid flower will eventually yield a bad result. Lovely though it is, Bulbophyllum echinolabium produces the kind of stench that might make you think about alerting the Public Health Department, but only when you get really close. It reels in unsuspecting people the same way it would lure a fly, with brilliant red colors and long wafting sepals, until nose meets flower, then there are cries of outrage and indignation. Don't say I didn't warn you.

Tuesday, July 12, 2016

The Greens of Summer

Green is a richly varied corner of the floral color spectrum. In summer it is a part of the spectrum my eye rests upon with deep appreciation. Lime, kiwi and melon hues -I think of them as a cool dessert after a steady diet of overheated tropical colors. Let's take a walk through the greenhouse and savor some of the greens.

First is a real stunner. Clowesia russelliana is a frothy extravaganza of icy mint green flowers. If you look closely, you can see a touch of pink in the petals and sepals.

It produced far and away the best fragrance of the week -a wonderful mixture of vanilla, ginger and eucalyptus.

Male Catasetum pileatum flowers are a gorgeous creamy green. It's not very often that we produce female flowers (on the left) and male flowers (on the right) simultaneously on a Catasetum, so I was quick to get a capsule on this plant.

Notice the subtle chartreuse tinge on the lip of these truffle-shaped Catasetum luridum flowers.

The glossy lip of Catasetum expansum looks as though it has been dipped in egg yolk.

One of the pleasures of walking through the Orchid Display House is discovering a delightful color combination. Lycaste oculata with its kiwi green sepals and pure white petals seems to my eye to be the perfect summer pairing of colors. It's a shame that the greens are often overlooked. Be sure not to miss them on  your next visit to the Fuqua Orchid Center.

Sunday, July 10, 2016

Stanhopea costaricensis

July is just a little early for stanhopeas here. It will be another month before the flooodgates open. In the meantime, we had a magnificent Stanhopea costaricensis in flower in the Orchid Display House last week. The fragrance was just wonderful, with a hint of vanilla.

Our Stanhopea costaricensis  has deep red splashes of varying sizes on the lip and column and some fascinating leopard spots on the petals and sepals.

It's flower isn't quite as big as the really big boys- Stanhopea tigrina, embreei and platyceras, but big enough that I had to back the camera way up in order to get the entire flower and pedicel in the frame.

Seen from above, the elongated lip has a diamond shaped hypochile.

The column has prominent wings.

Stanhopea costaricensis grows as an epiphyte in Central America between 500 and 1500 meters elevation. It grow without any problems in our intermediate greenhouse (60ยบ night minimum) in 60% shade. And it makes an impressive specimen sized (12") basket with outstandingly fragrant flowers.

Saturday, July 2, 2016

Two Miniatures

Two of our miniature orchids are generating a lot of excitement this week. Dyakia hendersoniana, all of five inches tall, has the kind of electric fuchsia coloring that is visible across the greenhouse.

Dyakia hendersoniana grows as an epiphyte in primary and old secondary forests from 0 to 700 meters elevation in areas of high rainfall on the island of Borneo. The column and lip are white, and the lip has an elongated spur.

Since my reference states that this is now a very rare species and endangered in the wild, I took this minute specimen to my office for pollinating. Tiny orchid flowers with spurs are (for me at least) one of the supreme challenges in orchid pollination. Removing the tiny anther cap and maneuvering the two pollinia into the stigmatic cavity without dropping them into the spur or onto my desk requires enormous patience and a steady hand. Usually, after I've dropped a few and I finally have the pollinia correctly positioned, they perversely refuse to release from the tip of my pencil. I am, as ever, amazed that insects can effortlessly accomplish this.

Pleurothallis tripterantha makes a perfect tiny specimen plant with pendant chains of honey colored flowers. It is an undemanding little plant that seems to always be in flower (perfect, in other words). We grow our plant in an intermediate temperature greenhouse in 80% shade. Pleurothallis tripterantha is widely distributed from Costa Rica through northern South America in wet montane forests at 900 to 2700 meters elevation.

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